What to say — and what not to say — on a first date, according to science

What distinguishes a good first date from a bad one? It’s pretty much all on display in the famous double-date scene from “When Harry Met Sally.” Sally and her terrible date firmly disagree about important topics. Harry and his terrible date are politely uninterested in each other. Then comes the moment where both of their terrible dates click — with each other. “Nobody has ever quoted me back to me before,” Sally’s date says to Harry’s date in admiration.

First dates are a staple of romantic comedy. They are also the focus of a 55-page study from researchers at Stanford University and the University of California at Santa Barbara that looks at what people say on successful dates and not-so-successful dates.